U.S. Pat. No. 3,982,415, which is assigned to the assignee of the present invention, discloses a machine having apparatus for splining an annular thin-wall sleeve of a power transmission member by meshing die and mandrel teeth with the sleeve located therebetween such that the resultant forming thereof provides the splines. This spline forming process takes place in a rolling manner as a mandrel on which the power transmission member is mounted rotates upon movement of toothed dies in opposite directions on opposite sides of the mandrel. An end wall of the power transmission member is clamped against an end of the mandrel during the rolling process so as to insure precise forming of the splines. Clutch hubs for automatic transmissions of road vehicles is one usage for which this spline forming process has particular utility in replacing prior impacting operations used to form clutch hub splines, as discussed in the aforementioned patent.
Teeth of the dies disclosed by U.S. Pat. No. 3,982,415 have a progressive height as well as a progressively larger tooth thickness along the pitch line thereof from the leading end of each die toward its trailing end. The spline forming thus proceeds in a progressive manner both as to the depth and width of the splines as the meshing of the die and mandrel teeth takes place.
U.S. Pat. No. 4,028,922, which also is assigned to the assignee of the present invention, discloses apparatus having toothed dies with different groups of teeth that cooperate with a toothed mandrel to form splines in a thin-wall sleeve of a power transmission member by the rolling process discussed above. Each toothed die includes a first tooth group of farther spaced teeth that form a first set of splines in the thin-wall sleeve in cooperation with the mandrel, and a second group of closer spaced teeth of each die thereafter cooperate with the mandrel to form a second set of splines between the first set of splines while meshing with the first set. Finally, the splined sleeve is again meshed with farther spaced teeth to provide correction of any out of roundness.
One embodiment of the apparatus disclosed by U.S. Pat. No. 4,028,922 includes toothed dies in the form of elongated racks having a leading tooth group of farther spaced teeth and a trailing tooth group of closer spaced teeth which are driven in a reciprocating manner to provide the initial forming of the first set of splines, the subsequent forming of the second set of splines, and the final meshing of the farther spaced teeth to correct any out of roundness. Another embodiment of the apparatus is disclosed as including toothed dies in the form of elongated racks having a leading tooth group of farther spaced teeth and an intermediate tooth group of closer spaced teeth as well as a trailing tooth group of farther spaced teeth. These dies are driven in an opposite direction to each other without any reversal to provide the initial forming of the first set of splines, the subsequent forming of the second set of splines between the first set, and the final meshing of the farther spaced teeth to correct any out of roundness. In each of these embodiments, the groups of farther spaced teeth include partial teeth therebetween for preventing the sleeve being splined from taking on a "bell mouth" shape.
U.S. Pat. No. 4,155,237, which is likewise assigned to the assignee of the present invention, discloses an automatic loader for a machine that splines thin-wall sleeves of power transmission members by the rolling process discussed above.